Article of footwear having a polygon lug sole pattern

ABSTRACT

Articles of footwear, including athletic footwear, include one or more of: (a) an upper; (b) a sole structure including a midsole and an outsole, the outsole having a plurality of polygonal lugs arranged about a base surface of the outsole. The outsole may include one or more regions wherein the characteristics of a portion of the lugs within a region differ from the characteristics of a portion of the lugs in another region. The lugs may differ, for example based on size, construction and/or spacing between the lugs. Methods of manufacturing such articles of footwear also are disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/459,689 filed Aug. 14, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/456,612 filed Apr. 26, 2012 (now U.S. Pat. No.8,832,970), which is a continuation of U.S. patent application Ser. No.12/039,072, filed Feb. 28, 2008 (now U.S. Pat. No. 8,186,078), whichapplication claims the benefit of U.S. Provisional Application No.60/892,129, entitled “Article of Footwear Having a Polygon Lug SolePattern,” filed on Feb. 28, 2007, which said applications areincorporated herein by reference in their entireties.

TECHNICAL FIELD

Aspects of the invention relate to articles of footwear. Morespecifically, aspects of the invention relate to articles of footwearhaving a sole structure with polygonal protrusions extending downwardforming a ground contacting surface.

BACKGROUND

Conventional articles of athletic footwear generally include two primaryelements, an upper and a sole structure. The upper is secured to thesole structure and forms a void on the interior of the footwear forcomfortably and securely receiving a foot. The upper, in at least somefootwear structures, generally extends over the instep and toe areas ofthe foot, along the medial and lateral sides of the foot, and around theheel area of the foot. In some articles of footwear, such as basketballfootwear and boots, the upper may extend upward and around the ankle toprovide support for the ankle. Access to the void in the interior of thefootwear is generally provided by an access opening. A lacing or otherfootwear securing system often is incorporated into the upper toselectively increase the size of the access opening and to permit thewearer to modify certain dimensions of the upper, particularly girth, toaccommodate feet with varying dimensions and to allow for easy footinsertion and removal. In addition, the upper further may include atongue that extends under the lacing system to enhance comfort of thefootwear and a heel counter to limit movement of the heel.

Various materials are conventionally utilized in manufacturing uppers.The upper of athletic footwear, for example, may be formed from multiplematerial layers that include an exterior layer, an intermediate layer,and an interior layer. The materials forming the exterior layer of theupper may be selected based upon the properties of wear-resistance,flexibility, and air-permeability, for example. With regard to theexterior layer, the toe area and the heel area may be formed of leather,synthetic leather, or a rubber material to impart a relatively highdegree of wear-resistance. Leather, synthetic leather, and rubbermaterials, however, may not exhibit the desired degree of flexibilityand air-permeability for various other areas of the exterior layer ofthe upper. Accordingly, the other areas of the exterior layer may beformed from a synthetic textile, for example. The exterior layer of theupper may be formed, therefore, from numerous material elements thateach imparts different properties to the upper. The intermediate layerof the upper is conventionally formed from a lightweight polymer foammaterial that provides impact force attenuation and enhances comfort.Similarly, the interior layer of the upper may be formed of acomfortable and moisture-wicking textile that removes perspiration fromthe area immediately surrounding the foot. In some articles of athleticfootwear, the various layers may be joined with an adhesive, andstitching may be utilized to join elements within a single layer or toreinforce specific areas of the upper.

The sole structure is positioned between the upper and the ground, andit may include a polymer foam midsole and an outsole. The midsole isarranged between the upper and the outsole and attenuates ground (orother contact surface) reaction forces to lessen stresses upon the footand leg. The outsole forms a ground-engaging portion (or other contactsurface-engaging portion) of the sole structure and is formed from adurable and wear-resistant material. The outsole is generally connectedto a bottom surface of the midsole and provides cushioning and tractionto the wearer. The sole is formed of a flexible material to allow thearticle of footwear to flex with the motion of the foot. The solestructure also may include a sockliner or an insole member that ispositioned within the void and proximal a lower surface of the foot toenhance footwear comfort.

SUMMARY

One aspect of the invention relates to articles of footwear having anupper and a sole structure. The sole structure includes a midsoleconnected to the upper and an outsole having a base surface engaged withthe midsole and a plurality of lugs protruding generally perpendicularlytherefrom. The lugs may be polygonal in shape and may have a uniformshape from a distal end to a proximal end. The lugs may be arranged suchthat they are not in contact with each other, at least at their distalends. Some examples of different shapes that may be used for thepolygonal lugs are hexagonal, pentagonal, octagonal, and triangular.

Additional aspects of this invention relate to articles of footwear,including athletic footwear or other types of footwear. Articles offootwear in accordance with at least some examples of this invention mayinclude one or more of: (a) an upper; and (b) a sole structure connectedto the upper, the sole structure including a midsole and an outsole. Insome arrangements the outsole includes a plurality of polygonal lugsprotruding downward from a bottom surface of the outsole. The pluralityof polygonal lugs may have a uniform shape. The outsole may also includeone or more regions wherein the characteristics of the lugs in a firstregion may differ from the characteristics of the lugs in other regions.Some examples of characteristics that may differ between lugs of variousregions include: (a) width; (b) wall thickness; and (c) spacing betweenthe lugs.

Further aspects of this invention relate to methods of manufacturingarticles of footwear, e.g., of the various types described above. Suchmethods may include, for example: (a) forming a mold of an outsoledefining a base surface and including openings corresponding to aplurality of polygonal lugs; (b) filling the mold with polyurethane orother desired material; (c) removing excess polyurethane or othermaterial; (d) adding textile or leather (or other desired material) tothe mold; and (e) applying heat and/or pressure to form the final moldedproduct. One or more additional elements, structures, and/or features,may be incorporated into the overall footwear structure and/or footwearproduction method without departing from this invention.

The advantages and features of novelty characterizing various aspects ofthe invention are pointed out with particularity in the appended claims.To gain an improved understanding of the advantages and features ofnovelty, however, reference may be made to the following descriptivematter and the accompanying drawings that describe and illustratevarious embodiments and concepts related to the aspects of theinvention.

DESCRIPTION OF THE DRAWINGS

The foregoing Summary, as well as the following Detailed Description,will be better understood when read in conjunction with the accompanyingdrawings.

FIG. 1 is a lateral side elevational view of an example article offootwear having an outsole in accordance with aspects of the invention.

FIG. 2 is a medial side elevational view of this example article offootwear.

FIG. 3 is a top plan view of one example outsole of the article offootwear having a polygon lug pattern.

FIG. 4 is a cross-sectional view of the example outsole shown in FIG. 3taken along line A-A.

FIG. 5 is a cross-sectional view of one example polygonal lug of theoutsole shown in FIG. 3 illustrating various dimensions of the lug.

FIGS. 6A-6C are cross-sectional views taken along a vertical plane ofexample lugs illustrating various configurations.

FIGS. 7A-7D illustrate portions of outsoles having various alternatecross-sectional configurations for example lugs of the outsole of thearticle of footwear.

FIG. 8 is a top plan view of another example outsole of the article offootwear.

FIG. 9 is a top plan view of yet another example outsole of the articleof footwear.

DETAILED DESCRIPTION

The following discussion and accompanying figures disclose variousarticles of footwear having uppers with a polygonal lug pattern in theoutsole in accordance with examples and aspects of the presentinvention. Concepts related to the polygonal lug sole pattern aredisclosed with reference to various articles of athletic footwear havingconfigurations suitable, for example, for sports such as running,walking, and the like. The polygonal lug sole structure, however, is notsolely limited to footwear designed for these activities. Rather, theymay be incorporated into a wide range of athletic footwear styles,including shoes that are suitable for basketball, baseball,cross-training, football, rugby, soccer, tennis, and volleyball, forexample. In addition, the polygonal lug sole structure may beincorporated into footwear that is generally considered to benon-athletic, including a variety of casual shoes, sandals, boots,shower shoes, beach/water shoes, shoes for water sports and/or for usein wet conditions, etc. An individual skilled in the relevant art willappreciate, therefore, that the concepts disclosed herein with regard tothe polygonal lug sole structure may be applied to a wide variety offootwear styles, in addition to the specific styles discussed in thefollowing material and depicted in the accompanying figures.

I. General Description of Aspects of this Invention

1. Articles of Footwear

Aspects of this invention relate to articles of footwear, includingathletic footwear or other types of footwear, that include: (a) an upperforming a void for receiving a foot; (b) a sole structure having amidsole connected to an upper and an outsole, the outsole including aplurality of polygonal lugs; and (c) one or more regions within theoutsole that include lugs having varying size and performancecharacteristics. Further aspects of the invention relate to methods ofmanufacturing articles of footwear according to the structural aspectsdescribed.

Articles of footwear in accordance with at least some examples of theinvention may include additional or alternative features. For example,in some structures, the outsole may be connected to a midsole having aplurality of incisions or sipes formed in the sidewall of the midsole.

The polygonal lugs, when present, may take on a variety of forms withoutdeparting from this invention. For example, in some structures, thepolygonal lugs may comprise various shapes. For instance, the polygonallugs may be formed as (a) hexagonal; (b) pentagonal; (c) octagonal; and(d) triangular. The lugs may also be formed in various sizes and may beformed with differing wall thicknesses to provide additional support invarious regions of the outsole. The polygonal lugs may also be formed invarious configurations, including (a) uniform; (b) stepped; and (c)tapered configurations.

Articles of footwear in accordance with at least some aspects of theinvention may include an outsole having one or more regions. The regionsmay be identified based on characteristics of at least a portion of thelugs within a region. In some examples, the size and/or configuration ofthe lugs within a region may be different from the sizes and/orconfigurations of the lugs in another region. In addition, the lugs in agiven region may be spaced more or less closely than the lugs in otherregions.

Articles of footwear in accordance with at least some aspects of theinvention may include some or all of the above described features, aloneor in combination. Articles of footwear in accordance with the inventionalso may have additional features described herein that may be used incombination with the features described above.

2. Methods of Constructing Articles of Footwear

Further aspects of this invention relate to methods of manufacturingarticles of footwear, e.g., of the various types described above. Suchmethods may include, for example: (a) forming a mold of an outsoledefining a base surface and including a plurality of open spacescorresponding to plural polygonal lugs; (b) filling the mold withpolyurethane (or other desired material); (c) removing excesspolyurethane (or other desired material); (d) adding textile or leather(or other desired material) to the mold and (e) applying heat and/orpressure to form the final molded product.

Methods in accordance with examples of this invention may includeadditional steps, the above-noted steps may be changed in order, and/orvarious steps may be omitted or modified, without departing from thisinvention.

II. Detailed Description of Example Structures and Methods According tothe Invention

Specific examples of structures and methods according to the inventionare described in more detail below. The reader should understand thatthese specific examples are set forth merely to illustrate examples ofthe invention, and they should not be construed as limiting theinvention.

An article of footwear 100 is depicted in FIGS. 1-2 as including anupper 120 and a sole structure 130. For purposes of reference in thefollowing description, footwear 100 may be divided into three generalregions: a forefoot region 111, a midfoot region 112, and a heel region113, as illustrated in FIG. 1. Regions 111-113 are not intended todemarcate precise areas of footwear 100. Rather, regions 111-113 areintended to represent general areas of footwear 100 that provide a frameof reference during the following discussion. Although regions 111-113apply generally to footwear 100, references to regions 111-113 also mayapply specifically to upper 120, sole structure 130, or individualcomponents included within and/or formed as part of either upper 120 orsole structure 130.

Upper 120 is secured to sole structure 130 and defines a void or chamberfor receiving a foot. For purposes of reference, upper 120 includes alateral side 121, an opposite medial side 122, and a vamp or instep area123. Lateral side 121 is positioned to extend along a lateral side ofthe foot (i.e., the outside) and generally passes through each ofregions 111-113. Similarly, medial side 122 is positioned to extendalong an opposite medial side of the foot (i.e., the inside) andgenerally passes through each of regions 111-113. Vamp area 123 ispositioned between lateral side 121 and medial side 122 to correspondwith an upper surface or instep area of the foot. Vamp area 123, in thisillustrated example, includes a throat 124 having a lace 125 or otherdesired closure mechanism that is utilized in a conventional manner tomodify the dimensions of upper 120 relative the foot, thereby adjustingthe fit of footwear 100. Upper 120 also includes an ankle opening 126that provides the foot with access to the void within upper 120. Avariety of materials may be used for constructing upper 120, includingmaterials that are conventionally utilized in footwear uppers.Accordingly, upper 120 may be formed from one or more portions ofleather, synthetic leather, natural or synthetic textiles, polymersheets, polymer foams, mesh textiles, felts, non-woven polymers, orrubber materials, for example. The upper 120 may be formed from one ormore of these materials wherein the materials or portions thereof arestitched or adhesively bonded together, e.g., in manners that areconventionally known and used in the art.

Upper 120 may also include a heel element (not shown) and a toe element(not shown). The heel element, when present, may extend upward and alongthe interior surface of upper 120 in the heel region 113 to enhance thecomfort of footwear 100. The toe element, when present, may be locatedin forefoot region 111 and on an exterior surface of upper 120 toprovide wear-resistance, protect the wearer's toes, and assist withpositioning of the foot. In some embodiments, one or both of the heelelement and the toe element may be absent, or the heel element may bepositioned on an exterior surface of the upper 120, for example.Although the configuration of upper 120 discussed above is suitable forfootwear 100, upper 120 may exhibit the configuration of any desiredconventional or non-conventional upper structure without departing fromthis invention.

Sole structure 130 is secured to a lower surface of upper 120 and mayhave a generally conventional shape. The sole structure 130 may have amultipiece structure, e.g., one that includes a midsole 131, an outsole132, and a sockliner or insole member (not shown). Midsole 131 may beformed of polymer foam material, such as polyurethane,ethylvinylacetate, or other materials (such as phylon, phylite, etc.)that compress to attenuate ground or other contact surface reactionforces during walking, running, jumping, or other activities. In someexample structures according to this invention, the polymer foammaterial may encapsulate or include various elements, such as afluid-filled bladder or moderator, that enhance the comfort,motion-control, stability, and/or ground or other contact surfacereaction force attenuation properties of footwear 100. In still otherexample structures, the midsole 131 may include additional elements thatcompress to attenuate ground or other contact surface reaction forces.For instance, the midsole may include column type elements to aid incushioning and absorption of forces.

Outsole 132 is secured to a lower surface of midsole 131 in thisillustrated example footwear structure 100 and is formed of awear-resistant material, such as rubber or a flexible syntheticmaterial, such as polyurethane, that contacts the ground or othersurface during ambulatory or other activities. The material formingoutsole 132 may be manufactured of suitable materials and/or textured toimpart enhanced traction and slip resistance. The structure and methodsof manufacturing the outsole 132 will be discussed further below. Aninsole or sockliner is a thin, compressible member that may be locatedwithin the void in upper 120 and adjacent to a lower surface of the foot(or between the upper 120 and midsole 131) to enhance the comfort offootwear 100. In some arrangements, the insole or sockliner may beabsent.

The outsole 132 shown in FIGS. 1 and 2 includes a plurality of incisionsor sipes 136 in either or both sides of the outsole 132. These sipes 136may extend from the bottom of the outsole 132 to an upper portionthereof or to the midsole 131. In one arrangement, the sipes 136 mayextend from a bottom surface of the outsole 132 to a point halfwaybetween the bottom of the outsole 132 and the top of the outsole 132. Inanother arrangement, the sipes 136 may extend from the bottom of theoutsole 132 to a point greater than halfway to the top of the outsole132. In yet another arrangement, the sipes 136 may extend from thebottom of the outsole 132 to a point where the outsole 132 meets themidsole 131. The sipes 136 may provide additional flexibility to theoutsole 132, and thereby allow the outsole to more freely flex in thenatural directions in which the wearer's foot flexes. In addition, thesipes 136 may aid in providing traction for the wearer.

FIGS. 3 and 4 illustrate various aspects of one example embodiment of anoutsole 200 having a polygon lug pattern in accordance with thisinvention. As shown in FIGS. 3 and 4, this example outsole 200 includesa periphery 202, and at least a portion of the outsole 200 includes aplurality of protrusions or lugs 210 protruding outward from a basesurface of the outsole 200. The outsole 200 is generally connected tothe midsole (not shown in FIGS. 3 and 4) such that a top surface 204 ofthe outsole 200 is in contact with the midsole and a base surface 206 ofthe outsole 200 is in contact with the ground or other external contactsurface. In the example arrangement shown, the plurality of lugs 210 maybe formed in the bottom surface 206 of the outsole 200 such that theplurality of lugs 210 are arranged to protrude downward from the basesurface 206 to contact the ground or other surface during use. Forexample, the lugs 210 may be arranged so that a distal end 211 of eachlug 210 contacts the ground or other surface during use.

FIG. 4 is a cross-sectional view of an outsole 200 like that shown inFIG. 3 taken along line A-A. The top surface 204 of the outsole 200 maybe generally flat and may be connected to the midsole of the article offootwear. For instance, the outsole 200 may be connected to the midsoleor other portion of the footwear structure by stitching, bonding,adhesive or any other generally known method of attachment. The basesurface 206 of the outsole 200 may be generally flat and, when thearticle of footwear is placed on a contact surface, may be substantiallyparallel to the contact surface. In some arrangements, the outsole 200may include a slight upward curve 208 or other structure, toward themidsole, e.g., to aid in attachment and provide a more pleasingappearance. The outsole 200 and/or midsole surfaces may take on anydesired shapes and/or constructions, including shapes and/orconstructions that are generally known or used in the art.

With further reference to FIG. 4, the outsole 200 includes a pluralityof protrusions or lugs 210 formed therein. The lugs 210 in this examplestructure 200 are generally uniform in shape and may have a polygonalcross-section. As shown, the plurality of lugs 210 protrude generallyperpendicularly outward from the base surface 206 of the outsole 200.For instance, the lugs 210 generally protrude downward with the proximalend 213 of each lug 210 extending from or connected to the base surface206 of the outsole 200 and with the distal end 211 of each lug 210forming a portion of a ground contacting surface. In the arrangementshown, the outsole 200 may be connected at a bottom portion of themidsole such that the lugs 210 may protrude downward to a point at whichthe distal end 211 of the lug 210 remains past the bottom surface of themidsole. The height (H in FIG. 5) of each of the lugs 210 may begenerally uniform across the surface of the outsole 200, if desired, toprovide an even ground contacting surface. In one arrangement, theplurality of lugs 210 may be a height suitable to allow for cushioningand traction for the wearer and may also provide ample flexibility whenthe outsole 200 flexes. For instance, in one example arrangement, theplurality of lugs 210 may be between 1 mm and 50 mm, and in someexamples between 3 mm and 35 mm or even between 5 mm and 30 mm inheight. This depth to the base surface 206 may provide traction to theuser and may also allow for flexibility of the outsole 200 during usebecause the outsole can flex between the lugs 210.

Although in some arrangements the lugs 210 may be uniform in height,other size and construction characteristics of the lugs 210 may vary.For instance, the lugs 210 may vary in width or wall thickness. In somearrangements, the configuration of the lugs 210 may also vary. The lugs210 also may vary in height over the area of the shoe sole (e.g., asshown in FIGS. 1 and 2), to provide a comfortable surface for walking,running, jumping, or other activities.

Generally, the lugs 210 may vary in width (W in FIG. 5) fromapproximately 1 mm to 40 mm, and in some examples between 3 mm and 30 mmor even between 5 mm and 25 mm. In some arrangements discussed below,the size of each of the lugs 210 may depend on the position of the lug210 on the outsole 200. For instance, some larger lugs, such as lug 210a in FIG. 4, (e.g., those having a relatively wider width) may bepositioned in regions of the outsole 200 where additional support isneeded (i.e., areas where the foot strikes the ground with greaterforce). However, smaller lugs, such as lug 210 b in FIG. 4, (e.g., thosehaving a relatively narrower width) may be positioned in regions whereground contact is minimized and/or the contact force is somewhat less.

The lugs 210 may also vary in wall thickness (T in FIG. 5). Forinstance, in some arrangements, at least a portion of the lugs 210, oreven the entire lug 210, may be solid structures. Additionally oralternatively, the lugs 210 may be formed as hollow structures. Thehollow construction may aid in flexibility of each of the lugs 210 ofthe outsole 200. In arrangements utilizing the hollow construction, thewall thickness (T in FIG. 5) may vary, e.g., depending on the positionof the lug 210 on the outsole 200, the size of the lug 210, the expectedimpact force on the lug 210, or the like. For instance, in areas whereadditional support may be needed, the lugs 210 may be of a heartierconstruction which includes a wall thickness between 1 mm and 20 mm, andin some examples between 3 mm and 15 mm or even between 4 mm and 12 mm.In areas where less support may be needed, the lugs 210 may be formedwith thinner walls to aid in flexibility of the lugs 210 and to reduceweight. Not all walls of a lug 210 need to have the same thickness(although they may have the same thicknesses).

With reference to FIGS. 4 and 6A-6C, different embodiments of a polygonlug sole may include various lug configurations. In one examplearrangement shown in FIG. 4, the lugs 210 may vary in size but may havea generally uniform cross-sectional area. For instance, each individuallug may have a generally constant width from the proximal end 213 to thedistal end 211. A close-up view of one example lug according to thisarrangement is shown in FIG. 6A. A portion of the outsole 200′ is shownhaving a top surface 204′ to be connected to the midsole and a basesurface 206′ from which the lug 210′ protrudes or extends generallyperpendicular to the surface. The lug 210′ is shown having a constantwidth and wall thickness from the proximal end 213′ to the distal end211′.

FIG. 6B is a close-up view of an alternate arrangement of anotherexample lug 210″. In the arrangement of FIG. 6B, a portion of theoutsole 200″ is shown with the lug 210″ protruding or extendingdownward, generally perpendicular to the base surface 206″ of theoutsole 200″. The lug 210″ includes a stepped configuration wherein abase portion 215″ is formed at the proximal end 213″ of the lug 210″.The lug 210″ may have a different cross-sectional area at the baseportion 215″ than at the distal end 211″ of the lug 210″. For example,the base portion 215″ of the lug 210″ may be wider than the distalportion 217″. The distal portion 217″ may be somewhat narrower than thebase portion 215″. In one example arrangement, the base portion 215″ mayextend from the bottom surface 206″ of the outsole to a point abouthalfway to the distal end 211″ of the lug 210″. In yet anotherarrangement, the base portion 215″ of the lug 210″ may extend from thebottom surface 206″ of the outsole 200″ to a point more than halfway tothe distal end 211″ of the lug 210″. Although this arrangement mayinclude a change in the cross-sectional area of the lug 210″, the shapeof the lug 210″ still may be uniform from the proximal end 213″ of thelug 210″ to the distal end 211″. For example, the base portion 215″ andthe distal portion 217″ may be the same polygonal shape. This steppedconfiguration may provide additional flexibility to the lug and mayreduce weight associated with the outsole. If desired, the differentsize for the distal portion 217″ may be provided by adding a tractionelement to the bottom of the base portion 215″.

FIG. 6C illustrates a close-up view of yet another example configurationof a lug 210″. The outsole 200′″ is shown with the lug 210′″ protrudingor extending downward, generally perpendicular to the base surface 206′″of the outsole 200″. The lug 210′″ includes a tapered configurationwherein the proximal end 213′″ of the lug 210′″ is wider than the distalend 211′″. Thus the cross-sectional area of the lug 210′″ narrows fromthe proximal end 213′″ to the distal end 211″. This taperedconfiguration may provide additional stability to the lug 210′″ and mayreduce weight associated with the outsole.

Generally, embodiments of the polygonal lug sole pattern include lugsthat are generally uniform in shape. For example, each lug may beconstructed to have a shape substantially similar to the other lugs inthe outsole, as shown in FIGS. 3, 8 and 9. In one arrangement, the lugsmay be identical in size and shape. In another arrangement, the lugs maybe substantially similar in shape and may differ only in size or otherperformance characteristics. For example, the lugs may all be the sameshape polygon (i.e., triangular, hexagonal, pentagonal, etc.) but maydiffer in height, width, wall thickness or another size basedcharacteristic, as discussed above.

Further examples of the polygon lug sole pattern in accordance with theinvention are shown in FIGS. 8 and 9. In the embodiments shown, thepolygonal lugs have a hexagonal cross section. The hexagonal shape mayallow the lugs to be closely nested together in certain regions of theoutsole. In addition, hexagonal lugs of various sizes and performancecharacteristics may be used in different regions of the outsole.Examples of the arrangements of the lugs will be discussed more fullybelow. Although hexagonal lugs will be used throughout thisspecification as one example embodiment of the polygonal lug solestructure, the hexagonal shape is one example. The lugs may beconstructed in various shapes. Some examples of alternate shapes areshown in the portions of outsoles shown in FIGS. 7A-7D. For example, thelugs may have a pentagonal cross section, as shown in FIG. 7A, anoctagonal cross section, as shown in FIG. 7C, a triangular crosssection, as shown in FIG. 7D, and the like.

FIGS. 8 and 9 illustrate alternate example embodiments of a polygon lugsole structure having hexagonal polygons. FIG. 8 illustrates an outsole300 having one example arrangement. The outsole 300 includes asubstantially flat top surface (not shown) and a substantially flat basesurface 306. A plurality of lugs 310 protrudes or extends downward,generally perpendicular to the base surface 306. As shown in FIG. 8, thelugs 310 are arranged to cover at least a portion of the outsole 300(i.e., at least 50%). In one arrangement, the lugs 310 are arranged tocover substantially most of the base surface 306 of the outsole 300(i.e., at least 70% or at least 80%). An outer edge or perimeter 302 isshown on which no lugs are formed. This area 302 may be flat or mayinclude a slight upward curve for ease of attachment of the outsole 300to the midsole or to provide a more pleasing appearance for the outsole300.

The outsoles shown in FIGS. 8 and 9 may include one or more regions.Each region may include lugs having performance characteristics suitablefor that region and, in some arrangements, different from other regions.In general, the motion of the foot during running proceeds as follows:Initially, the heel strikes the ground, followed by the ball of thefoot. As the heel leaves the ground, the foot rolls forward so that thetoes make contact, and finally the entire foot leaves the ground tobegin another cycle (with this portion of the step, the toes can receivea substantial amount of force). In order to accommodate the variousforces incident on the foot (i.e., heel hitting the ground, footflexing, etc.), the characteristics of the lugs may vary depending onthe position of the lug on the outsole. For instance, in areas of highcontact force or pressure, such as the heel area or the ball of the footwhere the foot strikes the ground with a high degree of force, the lugsmay be larger or may have thicker walls to accommodate the forcesincident on these regions. Additionally or alternatively, the lugs inthe high pressure areas may be more closely packed. Other areas of theoutsole could be considered low pressure areas. These areas may includethe arch of the foot, some areas along the lateral side of the outsoleconnected to the heel area or the toe area and/or generally around theperimeter of the foot. The lugs in these low pressure areas may besmaller or may be made with somewhat thinner walls. Additionally oralternatively, the lugs in the low pressure areas may be less closelypacked that the lugs in the high pressure areas.

FIG. 8 illustrates one polygon lug sole arrangement wherein the outsole300 includes more than one region and wherein characteristics of thelugs 310 within a region vary depending on the location or position ofthe region. The lugs 310 of FIG. 8 are sectioned into at least tworegions, a high pressure or force bearing region, identified by lugs 310a shown with cross-hatch, and a low pressure or force bearing region,identified by lugs 310 b without cross-hatch. The high pressure or forcebearing region of FIG. 8 generally includes a portion of the centralregion of the outsole 300. The low pressure or force bearing region ofFIG. 8 includes the lugs 310 b around the central portion or at aperiphery of the central portion. The lugs 310 a in the high pressure orforce bearing region may include some that are larger in size (i.e.,have a greater width) than others within that region and/or than othersin the low pressure region. Additionally or alternatively, at least aportion of the lugs 310 a within this high pressure region may beconstructed having a greater wall thickness than other lugs in theoutsole. The increased size and/or wall thickness may provide a heartierlug having increased stability and impact attenuation properties inthese areas where the foot strikes the ground with a high degree offorce.

The lugs 310 b in the low pressure or force bearing region (shownwithout cross-hatch) may have physical and performance characteristicsthat differ from the lugs 310 a of the high pressure or force bearingregion. For instance, at least a portion of the lugs 310 b in the lowpressure or force bearing region may be smaller in size than at least aportion of the lugs 310 a in the high pressure or force bearing region.In addition, at least a portion of the lugs 310 b of the low pressureregion may have a wall thickness somewhat less than the wall thicknessof at least a portion of the lugs 310 a in the high pressure or forcebearing region. The construction of the lugs 310 b in the low pressureor force bearing region may provide increased flexibility of the outsole300 and may reduce weight associated with the outsole.

In addition to potential differences in construction of the lugs in thedifferent regions, the positioning or spacing of the lugs relative toeach other may also differ based on the region. For instance, at least aportion of the lugs 310 a in the high pressure or force bearing regionmay be closely packed. In one example, the distance between neighboringlugs 310 a in the high pressure or force bearing region may be between 1mm and 15 mm, or even 1 mm and 8 mm. Arranging the lugs 310 a in thehigh pressure region in a tightly packed configuration may increasestability and cushioning in that portion of the outsole 300.

Additionally or alternatively, at least a portion of the lugs 310 b ofthe low pressure or force bearing region may be placed further apartthan at least a portion of those in the high pressure or force bearingregion. For instance, the spacing in the low pressure or force bearingregion between neighboring lugs 310 b may be between 1.5 mm and 20 mm,or even between 2 mm and 12 mm. Providing increased spacing between thelugs 310 b of the low pressure or force bearing region may provideincreased flexibility in that region of the outsole 300. For example, asthe outsole 300 flexes during use, the increased spacing between thelugs 310 b around the periphery of the outsole may aid in permitting theoutsole 300 to bend more freely between the lugs 310 b.

Although the spacing of the lugs may differ depending on the position ofthe lug on the outsole or the region, in the arrangements shown, thelugs are generally not in direct contact with each other. For instance,when the outsole is in a non-flexed position (i.e., resting flat on acontact surface) neighboring lugs will have at least a minimal gapbetween them. The spacing between the lugs may permit the outsole tobend more freely and conform to foot flexation during movement.

The example spacing and sizing arrangement shown in FIG. 8 may also aidin attenuating the impact forces of the foot striking the ground byspreading the load across the surface of the foot. For instance, thelarger or thicker walled lugs may provide additional support in highpressure or force bearing areas, while the smaller or thinner walledlugs may provide less support but may aid in flexibility. Thisarrangement allows for increased load support in high pressure or forcebearing areas to provide an even impact-attenuating and tractionarrangement for the outsole.

FIG. 9 illustrates an alternate arrangement of an outsole 400 havingpolygonal lugs 410 with different physical and performancecharacteristics based on the position of the lug 410 on the outsole 400.The outsole 400 of FIG. 9 includes multiple regions with lugs 410 havingvarying characteristics. For instance, the outsole may include a highpressure or force bearing region (having lugs 410 a shown incross-hatch). The high pressure or force bearing region may include theheel area as well as a lateral side of the foot in a central area, i.e.,opposite the arch of the foot. In addition, the outsole 400 may includea high pressure or force bearing area in the toe region (i.e., beneaththe first toe of the wearer). These areas may generally receive themajority of the high pressure forces exerted on the foot during use. Inaddition, the outsole 400 may include a low pressure or force bearingregion (having lugs 410 b shown without cross-hatch). The low pressureor force bearing region may include the periphery of the outsole 400 andthe area just above the ball of the foot. These regions may receive thelowest degree of force exerted on the foot during use. The outsole 400of FIG. 9 also includes a third region (having lugs 410 c shown withstippling). The third region may include the central area of the foot(i.e., adjacent the arch) and may also include the region beneath thesecond through fifth toes of the user. The third region may receive amoderate degree of force during use. For example, the third region mayreceive less force than the high pressure or force bearing region butmore force than the low pressure or force bearing region.

The lugs 410 a, 410 b of the high and low pressure or force bearingregions in FIG. 9 may be substantially similar in construction andphysical characteristics to those of similar regions in FIG. 8. Thecharacteristics of the lugs 410 c of the third region may differ fromthose of the lugs 410 a, 410 b in the high pressure and low pressure orforce bearing regions. For instance, at least a portion of the lugs 410c of the third region may be sized between at least a portion of thosein the high pressure or force bearing region and those in the lowpressure or force bearing region. In addition, the lugs 410 c of thethird region may have a wall thickness between at least a portion ofthose in the high pressure or force bearing region and those in the lowpressure or force bearing region. Still further, the lugs 410 c of thethird region may be spaced more closely than those of the low pressureor force bearing region but not as tightly as those of the high pressureor force bearing region.

It should be noted that a portion of the lugs 410 may also includecharacteristics that are a combination of the characteristics of lugs indifferent regions. In one arrangement, at least a portion of the lugsmay be constructed having a stepped configuration, as shown in FIG. 6B.This configuration allows the distal portion to have characteristicsthat differ from those of the base portion. For example, the baseportion may have characteristics similar to those of the lugs 410 c inthe third region of FIG. 9, i.e., medium sized with wall thicknessbetween that of lugs 410 a, 410 b in the high and low pressure or forcebearing regions. However, the distal portion may have somecharacteristics similar to those of the high pressure or force bearingregion, i.e., increased wall thickness. This composite type arrangementmay allow for increased flexibility, stability and impact-attenuation incertain lugs.

Although FIGS. 8 and 9 indicate distinct regions for the lugs, it shouldbe noted that lugs of a certain size or structure are not limited to usewithin a single region. Rather, lugs of varying sizes may be used in allregions to more fully distribute the load across the foot. In addition,although outsoles illustrating two and three regions are shown, otherembodiments may be considered having more than three different regionswith lugs having still other characteristics.

Of course, a wide variety of specific footwear structures may takeadvantage of the various features described above without departing fromthis invention.

The outsole may be formed of any suitable material that may providetraction for the user, as well as at least a minimal level ofimpact-attenuation and/or flexibility. For instance, the outsole may beformed of rubber or a synthetic material having the desired properties,such as polyurethane and/or other suitable materials as are known andused in the art. The outsole may be constructed using any of severalknown methods including methods that are known and/or used in the art.Additionally or alternatively, the outsole may be formed using a castpolyurethane process. The cast polyurethane process may include forminga mold having the desired outsole shape. For instance, the mold mayinclude the substantially flat upper surface as well as polygonalportions for forming the lugs of the outsole. The outsole may then befilled with polyurethane. The excess polyurethane may be removed, e.g.,by scraping or squeegeeing it off the top of the mold. Once the excesspolyurethane is removed, a second material (e.g., textile or leatherforming the upper or the midsole) may be added to the mold. At thispoint, heat and pressure may be applied to the form the final moldedproduct. Cast polyurethane molding processes are conventional and knownto those skilled in the art.

III. Conclusion

The invention is disclosed above and in the accompanying drawings withreference to a variety of embodiments. The purpose served by thedisclosure, however, is to provide an example of the various featuresand concepts related to aspects of the invention, not to limit the scopeof aspects of the invention. One skilled in the relevant art willrecognize that numerous variations and modifications may be made to theembodiments described above without departing from the scope of theinvention, as defined by the appended claims.

The invention claimed is:
 1. A sole structure for an article offootwear, comprising: a base surface; and a first plurality of polygonallugs extending from the base surface, the first plurality of polygonallugs having a first plurality of free ends opposite the base surface arenot in contact with each other and wherein the free ends have distalsurfaces that are arranged to form a ground contacting surface of thesole structure, wherein the first plurality of polygonal lugs includes afirst polygonal lug having two adjacent sides nested within an areadefined by sides of a first pair of adjacent polygonal lugs, wherein thefirst plurality of polygonal lugs is arranged in a first region of thesole structure; and a second plurality of polygonal lugs extending fromthe base surface, the second plurality of polygonal lugs being arrangedto form the ground contacting surface of the sole structure, wherein thesecond plurality of polygonal lugs includes a second polygonal lughaving two adjacent sides nested within an area defined by sides of asecond pair of adjacent polygonal lugs, wherein the second plurality ofpolygonal lugs is arranged in a second region of the sole structuredifferent from the first region of the sole structure; and wherein eachlug of the first plurality of polygonal lugs has a hollow constructionwith a hollow portion enclosed by each distal surface; wherein the firstplurality of polygonal lugs and the second plurality of polygonal lugsare non-uniformly sized.
 2. The article of footwear of claim 1, whereinthe first plurality of polygonal lugs in the first region have a firstspacing arrangement; and wherein the second plurality of lugs in thesecond region have a second spacing arrangement different from the firstspacing arrangement.
 3. The sole structure of claim 2, wherein the firstplurality of polygonal lugs have a first wall thickness and the secondplurality of polygonal lugs have a hollow construction and a second wallthickness different from the first wall thickness.
 4. The sole structureof claim 3, wherein the first wall thickness is between 3 mm and 20millimeters.
 5. The article of footwear of claim 3, wherein the secondwall thickness is between 1 mm and 5 millimeters.
 6. The sole structureof claim 3, wherein the first region is arranged at a central portion ofthe ground contacting surface and the second region is arranged at aperiphery of the central portion.
 7. A sole structure for an article offootwear, comprising: a base surface; a first plurality of polygonallugs extending from the base surface, the first plurality of polygonallugs having a first plurality of free ends opposite the base surface arenot in contact with each other and wherein the free ends have distalsurfaces that are arranged to form a ground contacting surface of thesole structure, wherein the first plurality of polygonal lugs includes afirst polygonal lug having two adjacent sides nested within an areadefined by sides of a first pair of adjacent polygonal lugs, wherein thefirst plurality of polygonal lugs is arranged in a first region of thesole structure; a second plurality of polygonal lugs extending from thebase surface, the second plurality of polygonal lugs being arranged toform the ground contacting surface of the sole structure, wherein thesecond plurality of polygonal lugs includes a second polygonal lughaving two adjacent sides nested within an area defined by sides of asecond pair of adjacent polygonal lugs, wherein the second plurality ofpolygonal lugs is arranged in a second region of the sole structuredifferent from the first region of the sole structure; and a thirdplurality of polygonal lugs extending from the base surface, the thirdplurality of polygonal lugs being arranged to form the ground contactingsurface of the sole structure, wherein the third plurality of polygonallugs includes a second polygonal lug having two adjacent sides nestedwithin an area defined by sides of a second pair of adjacent polygonallugs, wherein the third plurality of polygonal lugs is arranged in athird region of the sole structure different from both the first regionand the second region of the sole structure; and wherein the firstplurality of polygonal lugs has a first lug characteristic, and thesecond plurality of polygonal lugs has a second lug characteristicdifferent than the first lug characteristic, and the third plurality ofpolygonal lugs has a third lug characteristic different than both thefirst lug characteristic and the second lug characteristic; and whereineach lug of the first plurality of polygonal lugs has a hollowconstruction with a hollow portion enclosed by each distal surface. 8.The sole structure of claim 7, wherein the first plurality of polygonallugs have a first wall thickness, the second plurality of polygonal lugshave a hollow construction and a second wall thickness, and the thirdplurality of polygonal lugs have a hollow construction and a third wallthickness, wherein the first wall thickness is different than the secondwall thickness.